论文标题
关于发射线星系强的光学变化的起源
On the Origin of the Strong Optical Variability of Emission-line Galaxies
论文作者
论文摘要
发射线星系（ELG）对于理解星系的形成和演变至关重要，而对它们的可变性知之甚少。在这里，我们报告了有关宇宙场中选择的ELG样品的光学变异性的研究，该样品在两个时期内有狭窄的波段观测值，分别$ \ gtrsim $ 12年。该样本分别在NB816和$ i'/i $ bands的$ Subaru $ telescope上观察到Suprime-Cam（SC）和Hyper Suprime-Cam（HSC）。仔细去除窄带滤波器的机翼效应后，我们检查了181个光谱镜确认的ELG样品中的光学变异性。我们发现0（0/68）HA发射器，11.9％（5/42）[OIII]发射器，0（0/71）[OII] [OII]发射器显示出显着的可变性（$ |Δm_{nb {nb} | \ geq 3 \ geq 3 \，nb，nb，nb，agn}观察。我们研究了使用三种方法，包括X射线光度，中红外活性和放射性驱动器，研究了活性银河核（AGN）。我们在此VAR-ELG样品中发现零明亮的AGN，但不能排除微弱AGN的贡献。我们发现SNE还可以主导VAR-ELG样本的可变性。所有VAR-ELG样品的HST/F814W图像中显示的合并形态与恒星形成的增强（即SNE活性）一致。
Emission-line galaxies (ELGs) are crucial in understanding the formation and evolution of galaxies, while little is known about their variability. Here we report the study on the optical variability of a sample of ELGs selected in the COSMOS field, which has narrow-band observations in two epochs separated by $\gtrsim$ 12 years. This sample was observed with Suprime-Cam (SC) and Hyper Suprime-Cam (HSC) on the $Subaru$ telescope in NB816 and $i'/i$ bands, respectively. After carefully removing the wing effect of a narrow-band filter, we check the optical variability in a sample of 181 spectroscopically confirmed ELGs. We find that 0 (0/68) Ha emitters, 11.9% (5/42) [OIII] emitters, and 0 (0/71) [OII] emitters show significant variability ($|Δm_{NB}| \geq 3\,σ_{Δm_{NB,AGN}} = 0.20\, mag$) in the two-epoch narrow-band observations. We investigate the presence of active galactic nucleus (AGN) in this variable ELG (var-ELG) sample with three methods, including X-ray luminosity, mid-infrared activity, and radio-excess. We find zero bright AGN in this var-ELG sample, but cannot rule out the contribution from faint AGN. We find that SNe could also dominate the variability of the var-ELG sample. The merger morphology shown in the HST/F814W images of all the var-ELG sample is in agreement with the enhancement of star formation, i.e., the SNe activity.
